I usually do not cross-post from my Living Single blog. Instead, I write different posts for Psychology Today and All Things Single, with the latter sometimes a bit more personal. In case there are people who read this blog but not my Living Single blog, I wanted to repost about Friendsight: What Friends Know that Others Don’t.

In the very first course I ever taught as a faculty member, an undergraduate proposed a simple study. Dot Brauer wanted to show pairs of friends pictures of facial expressions and body postures to see how friends would compare to strangers in their reading of the nonverbal cues. Would two friends interpret the same nonverbal cues more similarly than two strangers?

You probably know intuitively what lots of research has shown – friends are often similar to each other in many ways. They often share attitudes, values, and interests. They are often the same sex and about the same age. Of course, there are lots of fascinating exceptions. The general rule, though, is not surprising.

But would it apply to the ways that friends interpret their interpersonal worlds? Even without consulting with each other, would two friends look at the same facial expression or body posture and think the same thing about what that person was feeling?

In the study that Dot Brauer and I did, the answer – with regard to facial expressions (but not postures) – was yes. Two friends were highly likely to agree with each other about the meaning of the facial expressions (they were given two choices each time), whereas pairs of strangers agreed no more often than would be expected by chance.

We wanted to know more about the pairs of friends, so we also asked each of them to indicate whether they discussed a variety of topics with each other. There were some very intimate topics on the list, as well as moderately intimate ones and some causal ones. That mattered. The more different topics the friends discussed with each other – especially the intimate ones – the more similar they were in how they interpreted facial expressions.

It was an intriguing study and we published it as a research note (not bad for Dot, who was an undergraduate and the first author!). In some ways, though, it was just suggestive. The friends were all women, we only recruited 20 friends (10 pairs), and the nonverbal communications were only in photographs, not videos.

Happily for me, more than a decade later, two colleagues who were then graduate students wanted to pursue this further. Matthew Ansfield and Kathy Bell and I videotaped women and men as they watched different kinds of slides. Some were pleasant (nice scenes, cute babies), some were unpleasant (scenes from surgery, images of burn victims), and others were unusual (odd photographic effects). Each person watched the slides alone and did not learn until later that they were being videotaped.

About a year later, 10 men and 12 women returned, and each brought a friend of the same sex. Everyone watched slides of people of their own sex. The slides always included the person in the study and strangers. So, the original participants watched videotapes of their own facial expressions and strangers’ facial expressions. The companions watched the facial expressions of their friend (who appeared on the videotape) and the strangers.

Now we had six different measures of whether friends were similar to each other in how they interpreted facial expressions. Did they agree on what the person on the tape was feeling when that person was a stranger and was watching a pleasant slide? An unpleasant slide? An unsual slide? What about when that person was familiar because it was a friend or (for the original participants) the participant him- or herself?

For the friends who were women, the answer was clear and compelling. In all six instances, the female friends agreed with each other much more often than pairs of female strangers did. (For the statistical junkies out there, the intraclass correlations ranged from .50 to .80. Like I said, compelling!)

It was a whole different story for the pairs of men. In five of the six nonverbal interpretation tasks, the male friends agreed with each other no more often than pairs of men who were complete strangers to each other. The one exception occurred when the men were watching other men who were strangers to them and who were watching unpleasant slides.

Remember, all anyone ever sees in the videoclips are the participants’ facial expressions. They have no idea which slides the participants are watching.

Just from watching 10 seconds of a person’s facial expression, two female friends interpret that facial expression similarly. It doesn’t matter whether they are watching someone familiar or unfamiliar, or whether the person in question is watching something pleasant or unpleasant or unusual. For the men, though, two friends only agree with each other more often than two strangers do if they are watching another man they do not know, who is looking at an unpleasant scene.

The smart and inquisitive students and colleagues just kept showing up, ready and eager to learn more about how friends compare to strangers in how they interpret each other’s nonverbal behaviors and those of strangers. Weylin Sternglanz and I found that there are times when friends who are not so close are actually more insightful than the closer friends about what the other is feeling.

Later, my colleagues and I looked more specifically at deception. Are friends more honest with each other than they are with strangers? Over time, do friends learn to detect each other’s deception more accurately? (Hint: Only some of them do.)

Something new is happening among scholars and in society more generally.  After decades of obsessing about romantic relationships, more and more people are recognizing the importance of friendship in so many of our lives – including the lives of people who are single and coupled. For a very long time, hardly anyone asked me about the friendship theme in the research I had conducted over the past decades. Now, I get asked about that much more often.

Partly in response to that growing interest, I have put together five of my journal articles on friendship. The new collection is a brief book called Friendsight: What Friends Know that Others Don’t. (You can get the paperback here or at Amazon; there is also a Kindle version.) Because these papers were originally published in academic journals, the results sections are blighted with statistics. However, the other sections (the introduction, the methods section, and the discussion section) should be readable to just about anyone.

Some of you know that since 2008, I’ve been working on what I hoped would be a new book about friendship that would draw from these studies and so many others. I read hundreds of articles, filled my shelves with friendship books, and wrote dozens of pages of notes. But I got scooped – someone got to this before I did. So Friendsight may end up being my only book that is primarily about friendship.

If you are interested in my book-publishing backstory, you can read more about it at All Things Single (here and here).

Two more important notes:

First:  Our friend Rachel Buddeberg is offering a Singles Empowerment Workshop. I asked her to tell us about it. You can find that post here at All Things Single. It is the post that directly precedes this one.

Second: In response to an earlier post at Living Single, Stopping singlism: What will work?, readers posted some wonderful stories of how they have stood up to singlism. Their experiences, in turn, inspired me to include such stories in a book I’m putting together on singlism. If you have stories you are willing to share in print, I’d love to hear from you. At the end of the post here at All Things Single, “My book-publishing backstory: Part 2,” you can read more about the project and the information I’m looking for. As you will see, I’m also interested in your experiences of realizing that you are (or are not) single at heart.